Question

The ratio of the area of a circle to the circumference of the circle (%20" id="TexFormula1" title=" \frac{A}{C} " alt=" \frac{A}{C} " align="absmiddle" class="latex-formula">) is $\frac{7}{1}$. Find the circumference of the circle. Leave your answer in terms of pi.

Answer 1

$\dfrac{\pi r^2}{2\pi r}=\dfrac{7}{1}\\ \dfrac{r}{2}=\dfrac{7}{1}\\ r=14\\\\ C=2\pi \cdot14=28\pi$